mirror of
https://github.com/ilyakooo0/nixpkgs.git
synced 2024-10-20 20:19:39 +03:00
478 lines
14 KiB
C
478 lines
14 KiB
C
#define _GNU_SOURCE
|
|
#include <stdio.h>
|
|
#include <stdarg.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <dlfcn.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <fcntl.h>
|
|
#include <limits.h>
|
|
#include <string.h>
|
|
#include <spawn.h>
|
|
#include <dirent.h>
|
|
|
|
#define MAX_REDIRECTS 128
|
|
|
|
#ifdef __APPLE__
|
|
struct dyld_interpose {
|
|
const void * replacement;
|
|
const void * replacee;
|
|
};
|
|
#define WRAPPER(ret, name) static ret _libredirect_wrapper_##name
|
|
#define LOOKUP_REAL(name) &name
|
|
#define WRAPPER_DEF(name) \
|
|
__attribute__((used)) static struct dyld_interpose _libredirect_interpose_##name \
|
|
__attribute__((section("__DATA,__interpose"))) = { &_libredirect_wrapper_##name, &name };
|
|
#else
|
|
#define WRAPPER(ret, name) ret name
|
|
#define LOOKUP_REAL(name) dlsym(RTLD_NEXT, #name)
|
|
#define WRAPPER_DEF(name)
|
|
#endif
|
|
|
|
static int nrRedirects = 0;
|
|
static char * from[MAX_REDIRECTS];
|
|
static char * to[MAX_REDIRECTS];
|
|
|
|
static int isInitialized = 0;
|
|
|
|
// FIXME: might run too late.
|
|
static void init() __attribute__((constructor));
|
|
|
|
static void init()
|
|
{
|
|
if (isInitialized) return;
|
|
|
|
char * spec = getenv("NIX_REDIRECTS");
|
|
if (!spec) return;
|
|
|
|
// Ensure we only run this code once.
|
|
// We do not do `unsetenv("NIX_REDIRECTS")` to ensure that redirects
|
|
// also get initialized for subprocesses.
|
|
isInitialized = 1;
|
|
|
|
char * spec2 = malloc(strlen(spec) + 1);
|
|
strcpy(spec2, spec);
|
|
|
|
char * pos = spec2, * eq;
|
|
while ((eq = strchr(pos, '='))) {
|
|
*eq = 0;
|
|
from[nrRedirects] = pos;
|
|
pos = eq + 1;
|
|
to[nrRedirects] = pos;
|
|
nrRedirects++;
|
|
if (nrRedirects == MAX_REDIRECTS) break;
|
|
char * end = strchr(pos, ':');
|
|
if (!end) break;
|
|
*end = 0;
|
|
pos = end + 1;
|
|
}
|
|
|
|
}
|
|
|
|
static const char * rewrite(const char * path, char * buf)
|
|
{
|
|
if (path == NULL) return path;
|
|
for (int n = 0; n < nrRedirects; ++n) {
|
|
int len = strlen(from[n]);
|
|
if (strncmp(path, from[n], len) != 0) continue;
|
|
if (snprintf(buf, PATH_MAX, "%s%s", to[n], path + len) >= PATH_MAX)
|
|
abort();
|
|
return buf;
|
|
}
|
|
|
|
return path;
|
|
}
|
|
|
|
static char * rewrite_non_const(char * path, char * buf)
|
|
{
|
|
// as long as the argument `path` is non-const, we can consider discarding
|
|
// the const qualifier of the return value to be safe.
|
|
return (char *)rewrite(path, buf);
|
|
}
|
|
|
|
static int open_needs_mode(int flags)
|
|
{
|
|
#ifdef O_TMPFILE
|
|
return (flags & O_CREAT) || (flags & O_TMPFILE) == O_TMPFILE;
|
|
#else
|
|
return flags & O_CREAT;
|
|
#endif
|
|
}
|
|
|
|
/* The following set of Glibc library functions is very incomplete -
|
|
it contains only what we needed for programs in Nixpkgs. Just add
|
|
more functions as needed. */
|
|
|
|
WRAPPER(int, open)(const char * path, int flags, ...)
|
|
{
|
|
int (*open_real) (const char *, int, mode_t) = LOOKUP_REAL(open);
|
|
mode_t mode = 0;
|
|
if (open_needs_mode(flags)) {
|
|
va_list ap;
|
|
va_start(ap, flags);
|
|
mode = va_arg(ap, mode_t);
|
|
va_end(ap);
|
|
}
|
|
char buf[PATH_MAX];
|
|
return open_real(rewrite(path, buf), flags, mode);
|
|
}
|
|
WRAPPER_DEF(open)
|
|
|
|
// In musl libc, open64 is simply a macro for open
|
|
#if !defined(__APPLE__) && !defined(open64)
|
|
WRAPPER(int, open64)(const char * path, int flags, ...)
|
|
{
|
|
int (*open64_real) (const char *, int, mode_t) = LOOKUP_REAL(open64);
|
|
mode_t mode = 0;
|
|
if (open_needs_mode(flags)) {
|
|
va_list ap;
|
|
va_start(ap, flags);
|
|
mode = va_arg(ap, mode_t);
|
|
va_end(ap);
|
|
}
|
|
char buf[PATH_MAX];
|
|
return open64_real(rewrite(path, buf), flags, mode);
|
|
}
|
|
WRAPPER_DEF(open64)
|
|
#endif
|
|
|
|
WRAPPER(int, openat)(int dirfd, const char * path, int flags, ...)
|
|
{
|
|
int (*openat_real) (int, const char *, int, mode_t) = LOOKUP_REAL(openat);
|
|
mode_t mode = 0;
|
|
if (open_needs_mode(flags)) {
|
|
va_list ap;
|
|
va_start(ap, flags);
|
|
mode = va_arg(ap, mode_t);
|
|
va_end(ap);
|
|
}
|
|
char buf[PATH_MAX];
|
|
return openat_real(dirfd, rewrite(path, buf), flags, mode);
|
|
}
|
|
WRAPPER_DEF(openat)
|
|
|
|
WRAPPER(FILE *, fopen)(const char * path, const char * mode)
|
|
{
|
|
FILE * (*fopen_real) (const char *, const char *) = LOOKUP_REAL(fopen);
|
|
char buf[PATH_MAX];
|
|
return fopen_real(rewrite(path, buf), mode);
|
|
}
|
|
WRAPPER_DEF(fopen)
|
|
|
|
#ifdef __GLIBC__
|
|
WRAPPER(FILE *, __nss_files_fopen)(const char * path)
|
|
{
|
|
FILE * (*__nss_files_fopen_real) (const char *) = LOOKUP_REAL(__nss_files_fopen);
|
|
char buf[PATH_MAX];
|
|
return __nss_files_fopen_real(rewrite(path, buf));
|
|
}
|
|
WRAPPER_DEF(__nss_files_fopen)
|
|
#endif
|
|
|
|
// In musl libc, fopen64 is simply a macro for fopen
|
|
#if !defined(__APPLE__) && !defined(fopen64)
|
|
WRAPPER(FILE *, fopen64)(const char * path, const char * mode)
|
|
{
|
|
FILE * (*fopen64_real) (const char *, const char *) = LOOKUP_REAL(fopen64);
|
|
char buf[PATH_MAX];
|
|
return fopen64_real(rewrite(path, buf), mode);
|
|
}
|
|
WRAPPER_DEF(fopen64)
|
|
#endif
|
|
|
|
#ifdef __linux__
|
|
WRAPPER(int, __xstat)(int ver, const char * path, struct stat * st)
|
|
{
|
|
int (*__xstat_real) (int ver, const char *, struct stat *) = LOOKUP_REAL(__xstat);
|
|
char buf[PATH_MAX];
|
|
return __xstat_real(ver, rewrite(path, buf), st);
|
|
}
|
|
WRAPPER_DEF(__xstat)
|
|
#endif
|
|
|
|
#ifdef __linux__
|
|
WRAPPER(int, __xstat64)(int ver, const char * path, struct stat64 * st)
|
|
{
|
|
int (*__xstat64_real) (int ver, const char *, struct stat64 *) = LOOKUP_REAL(__xstat64);
|
|
char buf[PATH_MAX];
|
|
return __xstat64_real(ver, rewrite(path, buf), st);
|
|
}
|
|
WRAPPER_DEF(__xstat64)
|
|
#endif
|
|
|
|
WRAPPER(int, stat)(const char * path, struct stat * st)
|
|
{
|
|
int (*__stat_real) (const char *, struct stat *) = LOOKUP_REAL(stat);
|
|
char buf[PATH_MAX];
|
|
return __stat_real(rewrite(path, buf), st);
|
|
}
|
|
WRAPPER_DEF(stat)
|
|
|
|
WRAPPER(int, access)(const char * path, int mode)
|
|
{
|
|
int (*access_real) (const char *, int mode) = LOOKUP_REAL(access);
|
|
char buf[PATH_MAX];
|
|
return access_real(rewrite(path, buf), mode);
|
|
}
|
|
WRAPPER_DEF(access)
|
|
|
|
WRAPPER(int, posix_spawn)(pid_t * pid, const char * path,
|
|
const posix_spawn_file_actions_t * file_actions,
|
|
const posix_spawnattr_t * attrp,
|
|
char * const argv[], char * const envp[])
|
|
{
|
|
int (*posix_spawn_real) (pid_t *, const char *,
|
|
const posix_spawn_file_actions_t *,
|
|
const posix_spawnattr_t *,
|
|
char * const argv[], char * const envp[]) = LOOKUP_REAL(posix_spawn);
|
|
char buf[PATH_MAX];
|
|
return posix_spawn_real(pid, rewrite(path, buf), file_actions, attrp, argv, envp);
|
|
}
|
|
WRAPPER_DEF(posix_spawn)
|
|
|
|
WRAPPER(int, posix_spawnp)(pid_t * pid, const char * file,
|
|
const posix_spawn_file_actions_t * file_actions,
|
|
const posix_spawnattr_t * attrp,
|
|
char * const argv[], char * const envp[])
|
|
{
|
|
int (*posix_spawnp_real) (pid_t *, const char *,
|
|
const posix_spawn_file_actions_t *,
|
|
const posix_spawnattr_t *,
|
|
char * const argv[], char * const envp[]) = LOOKUP_REAL(posix_spawnp);
|
|
char buf[PATH_MAX];
|
|
return posix_spawnp_real(pid, rewrite(file, buf), file_actions, attrp, argv, envp);
|
|
}
|
|
WRAPPER_DEF(posix_spawnp)
|
|
|
|
WRAPPER(int, execv)(const char * path, char * const argv[])
|
|
{
|
|
int (*execv_real) (const char * path, char * const argv[]) = LOOKUP_REAL(execv);
|
|
char buf[PATH_MAX];
|
|
return execv_real(rewrite(path, buf), argv);
|
|
}
|
|
WRAPPER_DEF(execv)
|
|
|
|
WRAPPER(int, execvp)(const char * path, char * const argv[])
|
|
{
|
|
int (*_execvp) (const char *, char * const argv[]) = LOOKUP_REAL(execvp);
|
|
char buf[PATH_MAX];
|
|
return _execvp(rewrite(path, buf), argv);
|
|
}
|
|
WRAPPER_DEF(execvp)
|
|
|
|
WRAPPER(int, execve)(const char * path, char * const argv[], char * const envp[])
|
|
{
|
|
int (*_execve) (const char *, char * const argv[], char * const envp[]) = LOOKUP_REAL(execve);
|
|
char buf[PATH_MAX];
|
|
return _execve(rewrite(path, buf), argv, envp);
|
|
}
|
|
WRAPPER_DEF(execve)
|
|
|
|
WRAPPER(DIR *, opendir)(const char * path)
|
|
{
|
|
char buf[PATH_MAX];
|
|
DIR * (*_opendir) (const char*) = LOOKUP_REAL(opendir);
|
|
|
|
return _opendir(rewrite(path, buf));
|
|
}
|
|
WRAPPER_DEF(opendir)
|
|
|
|
#define SYSTEM_CMD_MAX 512
|
|
|
|
static char * replace_substring(char * source, char * buf, char * replace_string, char * start_ptr, char * suffix_ptr) {
|
|
char head[SYSTEM_CMD_MAX] = {0};
|
|
strncpy(head, source, start_ptr - source);
|
|
|
|
char tail[SYSTEM_CMD_MAX] = {0};
|
|
if(suffix_ptr < source + strlen(source)) {
|
|
strcpy(tail, suffix_ptr);
|
|
}
|
|
|
|
sprintf(buf, "%s%s%s", head, replace_string, tail);
|
|
return buf;
|
|
}
|
|
|
|
static char * replace_string(char * buf, char * from, char * to) {
|
|
int num_matches = 0;
|
|
char * matches[SYSTEM_CMD_MAX];
|
|
int from_len = strlen(from);
|
|
for(int i=0; i<strlen(buf); i++){
|
|
char *cmp_start = buf + i;
|
|
if(strncmp(from, cmp_start, from_len) == 0){
|
|
matches[num_matches] = cmp_start;
|
|
num_matches++;
|
|
}
|
|
}
|
|
int len_diff = strlen(to) - strlen(from);
|
|
for(int n = 0; n < num_matches; n++) {
|
|
char replaced[SYSTEM_CMD_MAX];
|
|
replace_substring(buf, replaced, to, matches[n], matches[n]+from_len);
|
|
strcpy(buf, replaced);
|
|
for(int nn = n+1; nn < num_matches; nn++) {
|
|
matches[nn] += len_diff;
|
|
}
|
|
}
|
|
return buf;
|
|
}
|
|
|
|
static void rewriteSystemCall(const char * command, char * buf) {
|
|
char * p = buf;
|
|
|
|
#ifdef __APPLE__
|
|
// The dyld environment variable is not inherited by the subprocess spawned
|
|
// by system(), so this hack redefines it.
|
|
Dl_info info;
|
|
dladdr(&rewriteSystemCall, &info);
|
|
p = stpcpy(p, "export DYLD_INSERT_LIBRARIES=");
|
|
p = stpcpy(p, info.dli_fname);
|
|
p = stpcpy(p, ";");
|
|
#endif
|
|
|
|
stpcpy(p, command);
|
|
|
|
for (int n = 0; n < nrRedirects; ++n) {
|
|
replace_string(buf, from[n], to[n]);
|
|
}
|
|
}
|
|
|
|
WRAPPER(int, system)(const char *command)
|
|
{
|
|
int (*_system) (const char*) = LOOKUP_REAL(system);
|
|
|
|
char newCommand[SYSTEM_CMD_MAX];
|
|
rewriteSystemCall(command, newCommand);
|
|
return _system(newCommand);
|
|
}
|
|
WRAPPER_DEF(system)
|
|
|
|
WRAPPER(int, mkdir)(const char *path, mode_t mode)
|
|
{
|
|
int (*mkdir_real) (const char *path, mode_t mode) = LOOKUP_REAL(mkdir);
|
|
char buf[PATH_MAX];
|
|
return mkdir_real(rewrite(path, buf), mode);
|
|
}
|
|
WRAPPER_DEF(mkdir)
|
|
|
|
WRAPPER(int, mkdirat)(int dirfd, const char *path, mode_t mode)
|
|
{
|
|
int (*mkdirat_real) (int dirfd, const char *path, mode_t mode) = LOOKUP_REAL(mkdirat);
|
|
char buf[PATH_MAX];
|
|
return mkdirat_real(dirfd, rewrite(path, buf), mode);
|
|
}
|
|
WRAPPER_DEF(mkdirat)
|
|
|
|
WRAPPER(int, unlink)(const char *path)
|
|
{
|
|
int (*unlink_real) (const char *path) = LOOKUP_REAL(unlink);
|
|
char buf[PATH_MAX];
|
|
return unlink_real(rewrite(path, buf));
|
|
}
|
|
WRAPPER_DEF(unlink)
|
|
|
|
WRAPPER(int, unlinkat)(int dirfd, const char *path, int flags)
|
|
{
|
|
int (*unlinkat_real) (int dirfd, const char *path, int flags) = LOOKUP_REAL(unlinkat);
|
|
char buf[PATH_MAX];
|
|
return unlinkat_real(dirfd, rewrite(path, buf), flags);
|
|
}
|
|
WRAPPER_DEF(unlinkat)
|
|
|
|
WRAPPER(int, rmdir)(const char *path)
|
|
{
|
|
int (*rmdir_real) (const char *path) = LOOKUP_REAL(rmdir);
|
|
char buf[PATH_MAX];
|
|
return rmdir_real(rewrite(path, buf));
|
|
}
|
|
WRAPPER_DEF(rmdir)
|
|
|
|
static void copy_temp_wildcard(char * dest, char * src, int suffixlen) {
|
|
int dest_len = strnlen(dest, PATH_MAX);
|
|
int src_len = strnlen(src, PATH_MAX);
|
|
memcpy(dest + dest_len - (6 + suffixlen), src + src_len - (6 + suffixlen), 6);
|
|
}
|
|
|
|
WRAPPER(int, mkstemp)(char *template)
|
|
{
|
|
int (*mkstemp_real) (char *template) = LOOKUP_REAL(mkstemp);
|
|
char buf[PATH_MAX];
|
|
char * rewritten = rewrite_non_const(template, buf);
|
|
int retval = mkstemp_real(rewritten);
|
|
if (retval >= 0 && rewritten != template) {
|
|
copy_temp_wildcard(template, rewritten, 0);
|
|
}
|
|
return retval;
|
|
}
|
|
WRAPPER_DEF(mkstemp)
|
|
|
|
WRAPPER(int, mkostemp)(char *template, int flags)
|
|
{
|
|
int (*mkostemp_real) (char *template, int flags) = LOOKUP_REAL(mkostemp);
|
|
char buf[PATH_MAX];
|
|
char * rewritten = rewrite_non_const(template, buf);
|
|
int retval = mkostemp_real(rewritten, flags);
|
|
if (retval >= 0 && rewritten != template) {
|
|
copy_temp_wildcard(template, rewritten, 0);
|
|
}
|
|
return retval;
|
|
}
|
|
WRAPPER_DEF(mkostemp)
|
|
|
|
WRAPPER(int, mkstemps)(char *template, int suffixlen)
|
|
{
|
|
int (*mkstemps_real) (char *template, int suffixlen) = LOOKUP_REAL(mkstemps);
|
|
char buf[PATH_MAX];
|
|
char * rewritten = rewrite_non_const(template, buf);
|
|
int retval = mkstemps_real(rewritten, suffixlen);
|
|
if (retval >= 0 && rewritten != template) {
|
|
copy_temp_wildcard(template, rewritten, suffixlen);
|
|
}
|
|
return retval;
|
|
}
|
|
WRAPPER_DEF(mkstemps)
|
|
|
|
WRAPPER(int, mkostemps)(char *template, int suffixlen, int flags)
|
|
{
|
|
int (*mkostemps_real) (char *template, int suffixlen, int flags) = LOOKUP_REAL(mkostemps);
|
|
char buf[PATH_MAX];
|
|
char * rewritten = rewrite_non_const(template, buf);
|
|
int retval = mkostemps_real(rewritten, suffixlen, flags);
|
|
if (retval >= 0 && rewritten != template) {
|
|
copy_temp_wildcard(template, rewritten, suffixlen);
|
|
}
|
|
return retval;
|
|
}
|
|
WRAPPER_DEF(mkostemps)
|
|
|
|
WRAPPER(char *, mkdtemp)(char *template)
|
|
{
|
|
char * (*mkdtemp_real) (char *template) = LOOKUP_REAL(mkdtemp);
|
|
char buf[PATH_MAX];
|
|
char * rewritten = rewrite_non_const(template, buf);
|
|
char * retval = mkdtemp_real(rewritten);
|
|
if (retval == NULL) {
|
|
return retval;
|
|
};
|
|
if (rewritten != template) {
|
|
copy_temp_wildcard(template, rewritten, 0);
|
|
}
|
|
return template;
|
|
}
|
|
WRAPPER_DEF(mkdtemp)
|
|
|
|
WRAPPER(char *, mktemp)(char *template)
|
|
{
|
|
char * (*mktemp_real) (char *template) = LOOKUP_REAL(mktemp);
|
|
char buf[PATH_MAX];
|
|
char * rewritten = rewrite_non_const(template, buf);
|
|
char * retval = mktemp_real(rewritten);
|
|
if (retval == NULL) {
|
|
return retval;
|
|
};
|
|
if (rewritten != template) {
|
|
copy_temp_wildcard(template, rewritten, 0);
|
|
}
|
|
return template;
|
|
}
|
|
WRAPPER_DEF(mktemp)
|